Strained layer quantum well structures present an interesting potential for optoelectronic and high speed device applications.We study the effect of strain on the energy levels of InxGa1-xAs /GaAs quantum well structures, in whichthe InxGa1-xAs layers are strained. Strain effects the band structure by increasing the band gap and splitting thevalence band , the heavy hole (HH) band lying at a higher energy than the light hole (LH) band, therby confining the heavy holes in the InxGa1-xAs and light holes in the GaAs layers. We analyse the strain and quantum size effects by considering a multiple finite quantum well potential structure. We vaiy the well width, barrier width, the number of the wells as well as the alloy concentration and calculate the optical transition between the conduction and valence band levels.